Demirbas (2002) reported that at the desired temperature, three different biomass
samples were subjected to direct and catalytic pyrolysis to obtain gaseous products
rich in hydrogen. The pyrolysis products are obtained into a volatile fraction
consisting of gaseous vapour and tar components and a carbon-rich solid residue.
The pyrolysis process consists of a very complex set of reactions in which radicals
are formed. Biomass gasification is a heat treatment that results in an increased
production of gaseous products and small amounts of coal and ash. Hydrogen is
produced from solid waste by pyrolysis. The untreated and catalyst-impregnated
samples were pyrolysed at temperatures of 775 K, 925 K, 975 K and 1025 K. As
temperature increases, there is increase in total volume and the gas yield.
Sonobe and Worasuwannarak (2008) investigated the behaviour of pyrolysis of
various agricultural residues using thermogravimetric analysis. The evolution rates
of gaseous products during pyrolysis, such as H 2 , CH 4 , H 2 O, CO and CO 2 , were also
measured using TG-MS techniques. Distribution activation energy model (DAEM)
proposed by Miura and Maki (1998) used to obtain kinetic parameter activation
energy f(E) and frequency factor k o (E) of the pyrolysis. Increases in values of f
(E) peaks of the f(E) curve for rice straw, rice waste, corn and cellulose were found to
be 170, 174, 183 and 185 kJ/mol, respectively, which increased by an order of 10
11
to an order of 10
18 s
À1
, while E increased from 120 to 250 kJ/mol. The variation of f
(E) curve of different types of biomass is due to the alkali and alkaline earth metal
catalytic during pyrolysis.
Adam et al. (2005) included four Al-MCM-41 type catalysts with an Si/Al ratio of
20. Mesoporous Al-MCM-41 catalysts were used to convert the pyrolysis vapours of
spruce wood into better bio-oil properties. The catalytic properties of the
Al-MCM-41 catalyst have been modified by the enlargement of the pores, allowing
the treatment of larger molecules and the introduction of Cu cations into the
structure. The pyrolysis of the spruce wood at 500
C was carried out, and the
products were analysed by means of online pyrolysis gas/mass spectrometry
(Py-GC/MS). In addition, thermogravimetry/mass spectrometry (TG/MS)
experiments were used to monitor the evolution of the product under slow heating
conditions (20
C/min) of 50 to 800
C. Levoglucosan is completely eliminated,
while acetic acid, furfural and furans become important components of the cellulose
pyrolysis products compared to the unmodified Al-MCM-41 catalyst. The dominance of high molecular weight phenolic compounds is greatly reduced among
lignin products. The increase in the yield of acetic acid and furan and the decrease
of large methoxyphenols are suppressed to some extent in comparison with dilated
pore catalysts. The Cu-modified catalyst exhibited a performance comparable to that
of the expanded pore size catalyst in converting pyrolysis vapours into wood,
although its pore size corresponded to that of unmodified Al-MCM-41.
Stefanidis et al. (2014) carried out thermogravimetric (TG) analyses as well as
rapid thermal and catalytic pyrolysis experiments of cellulose, hemicellulose, lignin
and their mixtures to study and determine their pyrolysis products if the pyrolysis
behaviour of a given lignocellulose-containing biomass is possible when the content
is known in these three components. The limited heat transfer had no significant
effect on the TG curves but affected the product distribution in the fast pyrolysis
338
S. Aswin et al.
samples were subjected to direct and catalytic pyrolysis to obtain gaseous products
rich in hydrogen. The pyrolysis products are obtained into a volatile fraction
consisting of gaseous vapour and tar components and a carbon-rich solid residue.
The pyrolysis process consists of a very complex set of reactions in which radicals
are formed. Biomass gasification is a heat treatment that results in an increased
production of gaseous products and small amounts of coal and ash. Hydrogen is
produced from solid waste by pyrolysis. The untreated and catalyst-impregnated
samples were pyrolysed at temperatures of 775 K, 925 K, 975 K and 1025 K. As
temperature increases, there is increase in total volume and the gas yield.
Sonobe and Worasuwannarak (2008) investigated the behaviour of pyrolysis of
various agricultural residues using thermogravimetric analysis. The evolution rates
of gaseous products during pyrolysis, such as H 2 , CH 4 , H 2 O, CO and CO 2 , were also
measured using TG-MS techniques. Distribution activation energy model (DAEM)
proposed by Miura and Maki (1998) used to obtain kinetic parameter activation
energy f(E) and frequency factor k o (E) of the pyrolysis. Increases in values of f
(E) peaks of the f(E) curve for rice straw, rice waste, corn and cellulose were found to
be 170, 174, 183 and 185 kJ/mol, respectively, which increased by an order of 10
11
to an order of 10
18 s
À1
, while E increased from 120 to 250 kJ/mol. The variation of f
(E) curve of different types of biomass is due to the alkali and alkaline earth metal
catalytic during pyrolysis.
Adam et al. (2005) included four Al-MCM-41 type catalysts with an Si/Al ratio of
20. Mesoporous Al-MCM-41 catalysts were used to convert the pyrolysis vapours of
spruce wood into better bio-oil properties. The catalytic properties of the
Al-MCM-41 catalyst have been modified by the enlargement of the pores, allowing
the treatment of larger molecules and the introduction of Cu cations into the
structure. The pyrolysis of the spruce wood at 500
C was carried out, and the
products were analysed by means of online pyrolysis gas/mass spectrometry
(Py-GC/MS). In addition, thermogravimetry/mass spectrometry (TG/MS)
experiments were used to monitor the evolution of the product under slow heating
conditions (20
C/min) of 50 to 800
C. Levoglucosan is completely eliminated,
while acetic acid, furfural and furans become important components of the cellulose
pyrolysis products compared to the unmodified Al-MCM-41 catalyst. The dominance of high molecular weight phenolic compounds is greatly reduced among
lignin products. The increase in the yield of acetic acid and furan and the decrease
of large methoxyphenols are suppressed to some extent in comparison with dilated
pore catalysts. The Cu-modified catalyst exhibited a performance comparable to that
of the expanded pore size catalyst in converting pyrolysis vapours into wood,
although its pore size corresponded to that of unmodified Al-MCM-41.
Stefanidis et al. (2014) carried out thermogravimetric (TG) analyses as well as
rapid thermal and catalytic pyrolysis experiments of cellulose, hemicellulose, lignin
and their mixtures to study and determine their pyrolysis products if the pyrolysis
behaviour of a given lignocellulose-containing biomass is possible when the content
is known in these three components. The limited heat transfer had no significant
effect on the TG curves but affected the product distribution in the fast pyrolysis
338
S. Aswin et al.